An empirical analysis was conducted to evaluate the effect of the micro-coiled tube geometries on the mixing performance. Micro-helically coiled tubes with various curvature ratios and torsions (twelve layouts) were applied in the experiments. The micromixing performance was studied using Villermaux/Dushman reaction in the laminar flow regime. The results show that the channel geometry has an efficient influence on the micromixing. The performance ratio was defined using measuring pressure drops to evaluate mixing and flow characteristics. The performance ratio for all layouts is more than one, and it is higher in larger curvature ratios. However, it decreases with increasing the torsion. The largest performance ratios obtained in the highest curvature ratio and the lowest torsion .It is about 98 % more than that of the micro-coiled tube with lowest curvature ratio and highest torsion. The genetic algorithm technique was applied to develop an empirical correlation for estimating the segregation index in micro-helically coiled tubes.
